Sheet handlers are well known and, generally, such sheet handlers have a defined path through which sheet material is transported to and from one or more process stations. In image input devices, electrophotographic devices, ink jet printing devices and other such devices, sheet handling devices are employed to sequentially transport sheet material (i.e., sheets of paper and paper-like substrates, such as mylar, vellum, and the like and hereinafter collectively referred to as sheets) to and from image processing stations, such as image input scanning devices, light-lens imaging devices, fusing stations, imprinting stations, transfer stations, and the like.
Sheet handlers of the type in which this invention useful include both sheet handlers which are known as document handlers for sequentially feeding individual documents from a document input station to a document image processing station and then to a document output station, as well as sheet handlers of the type for sequentially feeding individual copy sheets from a copy sheet input station, to a copy sheet imprinting station, and to a copy output station. In general, to restate the foregoing, a sheet handler is employed to transport the sheets to a processing station. Often at such processing stations it is necessary that the transported sheet not only be registered but also held or gripped in place. For example, in some color printers the copy sheet to be printed upon must be delivered to a belt with a registration edge. The sheet then must be gripped on the belt as the sheet is transported through several imaging stations as a composite color image is formed thereon. Likewise, imagining stations adapted for imaging large document also employ apparatus for registering the document to be imaged and gripping the document as it is transported through the imaging station. Other devices also use registering and gripping apparatus to register and hold a sheet in place while an imaging station is moved or otherwise actuated over the sheet to form an image on or from the sheet.
These devices are functional, and they produce reasonably satisfactory results. However, they also tend to be somewhat expensive, not entirely simple and low cost, and not always entirely effective. Thus, there exists a need for a relatively simple, low cost apparatus for registering and gripping sheets transported to a process station.
The following disclosures may be relevant to various aspects of the present invention.
U.S. Pat. No. 3,924,849, Patentee: Murakami, Issued: Dec. 9, 1975 PA1 U.S. Pat. No. 4,473,222, Patentee: Simmons et al., Issued: Sep. 25, 1984 PA1 U.S. Pat. No. 5,136,336, Patentee: Dastin et al., Issued: Aug. 4, 1992 PA1 EP-A-90850156.2, Publication No. 0399970, Filed: Apr. 24,1990, Inventor: Fujino PA1 U.S. Pat. No. 5,062,602, Patentee: Kress et al., Issued: Nov. 5,1991 PA1 U.S. Pat. No. 4,920,421, Patentee: Stemmie, Issued: Apr. 24, 1990 PA1 U.S. Pat. No. 4,848,762, Patentee: Beery, Issued: Jul. 18, 1989
U.S. Pat. No. 3,924,849 discloses a gripping device for use with a chain driven paper carriage comprising a gripper bar mounted between housing chances having a U-shaped configuration. One leg of the gripper bar is stripped of the upper extremity to form an inner, lower step and a higher outer step. Gripper members are biased into contact with the lower step to grip paper therebetween. An actuated cam is also employed to release the paper from the gripper members after processing and to receive additional paper.
U.S. Pat. No. 4,473,222 discloses an adjustable sheet handling apparatus which includes a member for engaging a sheet along a path. The member is movable into the path to engage a sheet and a second member connected to the engaging member is also movable into the sheet to hold the sheet in the path.
U.S. Pat. No. 5,136,336 discloses a gripper apparatus secured by a movable belt for gripping copy sheets moving in a path and transporting the sheet with the belt through a processing station. The sheet gripper includes an upper and lower gripper portion which is spring biased together. Cam members are provided to periodically open the gripper members to permit release of gripped sheets and to receive another sheet.
European Application No. 90850156.2, Publication No. 0399970 discloses an image scanning apparatus comprising a document feed mechanism which includes a light source and an image sensor reciprocally moved from a home position and a starting position. The document feeding mechanism is mechanically connected to the image sensing unit and moves with the sensing unit. The document feed mechanism includes a functional roller unit which contacts a glass platen, for positioning an image bearing surface face down, and which is coupled to a shaft through a one-way clutch. The clutch inhibits rotation of the roller during movement of the scanning unit and feed mechanism from the home position to the scan starting position and allows rotation during the reverse movement. An operator inserts a document in proper orientation between the frictional roller and the glass patent; the document is then fed or movement to the proper position by the movement of the scanning unit and the feed mechanism from the home position to the scanning position. The document is then scanned during the return movement of the feeder mechanism and s canning unit as the roller freely rotates on the document.
U.S. Pat. No. 5,062,602 discloses the use of a one-way fibrous cloth or pad material, which has fibers oriented toward the rear or upstream position of a feeder tray. The fibers engage the trailing or upstream edge of the sheet above the feed sheet as the feed sheet is fed from a bottom sheet feeder to functionally resist the downstream movement of the sheet above the feed sheet to reduce feeding of multiple sheets from the tray at one time.
U.S. Pat. No. 4,920,421 discloses a combined input and output scanner assembly including a copy sheet transport for transporting copy sheets through the assembly moving a scanning and printing assembly to enable the printing of the copy sheet.
U.S. Pat. No. 4,848,762 discloses a sheet feed apparatus for feeding a sheet from a stack of sheets. A plurality of sheet engaging pressure pads are employed to engage a sheet so that a sheet may be fed from planar and non-planar stacks.
The foregoing references failed to provide a relatively simple, sheet registering and gripping device for sheets transported to a processing station for processing.
In accordance with one aspect of the present invention, a sheet registration and gripping device for sheets transported by sheet handling apparatus is provided. The invention comprises a sheet registration edge including a first surface for registering the transported sheets, and a second surface substantially perpendicular to the first surface, a gripping surface positioned proximate to the registration edge, and means for moving the registration edge from a first position for registering sheets against the first surface to a second position for engaging sheets by the second surface and gripping sheets between the gripping surface and the second surface. The invention may further comprise a housing adapted to support the registration edge and the gripping surface. The invention in accordance with this aspect may additionally include second means for moving the registration edge to a third position locating the first and the second surfaces remote from the gripping surface to enable sheets to be transported past the first surface and the second surface. Other features of this aspect of the invention may also comprise means for resiliently urging the registration edge selectively to the first position, the second position and the third position, as well as a camming device for moving the registration edge in a direction opposite to the direction of movement urged by the resilient means. The camming device may be a cam which defines a track having said registration edge disposed therein. With the track having raised portions in the track for actuating said first and said second surfaces between the first and the second positions and with the track having laterally displaced portions in the track so as to move the registration edge laterally responsive to movement of the cam.
In accordance with another aspect of the present invention, there is provided a sheet registering and gripping apparatus for registering sheets transported along a path comprising a registration edge, a gripping edge extending from the registration edge, and means for substantially vertically actuating the registration edge so as to move the registration edge between a registering position and a gripping position. The invention in accordance with this aspect may further include means for actuating the registration edge laterally and vertically to move the registration edge and the gripping edge to a remote position enabling the transported sheets to pass the registration edge and the gripping edge.
In accordance with yet another aspect of the present invention a method for registering and gripping sheets transported along a path is provided which comprising the steps of engaging the transported sheets against a registration edge to register individual sheets, lowering the registration edge so that a gripping member extending substantially parallel to the registration edge grips a registered sheet in the path, and translating the registration edge in both a lateral and vertical manner to release a gripped sheet. The method of this aspect of the invention can include a part of the translating step moving the registration edge and the gripping member to a position in a remote location allowing transport of sheets in the path thereby. The method of this aspect of the invention can further include actuating a cam member connected to the registration edge and biasing the registration edge into contact with the cam member.